 /*******************************************************************************
  * Copyright (c) 2000, 2005 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
  * http://www.eclipse.org/legal/epl-v10.html
  *
  * Contributors:
  * IBM Corporation - initial API and implementation
  *******************************************************************************/
 package org.eclipse.core.internal.dtree;

 /**
  * An interface for comparing two data tree objects. Provides information
  * on how an object has changed from one tree to another.
  */
 public interface IComparator {
     /**
      * Returns an integer describing the changes between two data objects
      * in a data tree. The first three bits of the returned integer are
      * used during calculation of delta trees. The remaining bits can be
      * assigned any meaning that is useful to the client. If there is no
      * change in the two data objects, this method must return 0.
      *
      * @see NodeComparison
      */
     int compare(Object o1, Object o2);
 }

